From 40e7b29af85af541967a18a24421e6d3b7a6ee04 Mon Sep 17 00:00:00 2001
From: Rafal Kupiec <belliash@codingworkshop.eu.org>
Date: Fri, 8 Dec 2023 19:29:10 +0100
Subject: [PATCH] Implement BlpLoadConfigurationFile() routine

---
 xtldr2/config.c           | 57 +++++++++++++++++++++++++++++++++++++++
 xtldr2/includes/bootman.h |  6 +++++
 2 files changed, 63 insertions(+)

diff --git a/xtldr2/config.c b/xtldr2/config.c
index 45869f5..0ff3e73 100644
--- a/xtldr2/config.c
+++ b/xtldr2/config.c
@@ -9,6 +9,63 @@
 #include <xtldr.h>
 
 
+/**
+ * Loads configuration file from the specified directory on the FS0:/ drive.
+ *
+ * @param ConfigDirectory
+ *        Specifies a path to the directory containing the configuration file.
+ *
+ * @param ConfigFile
+ *        Specifies the name of the configuration file.
+ *
+ * @param ConfigData
+ *        Provides a buffer to store the data read from the configuration file.
+ *
+ * @return This routine returns status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlpLoadConfigurationFile(IN CONST PWCHAR ConfigDirectory,
+                         IN CONST PWCHAR ConfigFile,
+                         OUT PCHAR *ConfigData)
+{
+    PEFI_FILE_HANDLE DirHandle, FsHandle;
+    EFI_HANDLE DiskHandle;
+    EFI_STATUS Status;
+    SIZE_T FileSize;
+
+    /* Open EFI volume */
+    Status = BlOpenVolume(NULL, &DiskHandle, &FsHandle);
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to open a volume */
+        return Status;
+    }
+
+    /* Open specified directory, containing the configuration file and close the FS immediately */
+    Status = FsHandle->Open(FsHandle, &DirHandle, ConfigDirectory, EFI_FILE_MODE_READ, 0);
+    FsHandle->Close(FsHandle);
+
+    /* Check if directory opened successfully */
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to open directory */
+        BlCloseVolume(DiskHandle);
+        return Status;
+    }
+
+    /* Read configuration file */
+    Status = BlReadFile(DirHandle, ConfigFile, (PVOID *)ConfigData, &FileSize);
+
+    /* Close EFI volume */
+    BlCloseVolume(DiskHandle);
+
+    /* Return read status */
+    return STATUS_EFI_SUCCESS;
+}
+
 /**
  * Parses command line arguments and updates global configuration.
  *
diff --git a/xtldr2/includes/bootman.h b/xtldr2/includes/bootman.h
index cedf062..07aa835 100644
--- a/xtldr2/includes/bootman.h
+++ b/xtldr2/includes/bootman.h
@@ -141,6 +141,12 @@ BlpFindParentBlockDevice(IN PLIST_ENTRY BlockDevices,
                          IN PEFI_BLOCK_DEVICE_DATA ChildNode,
                          OUT PEFI_BLOCK_DEVICE_DATA ParentNode);
 
+XTCDECL
+EFI_STATUS
+BlpLoadConfigurationFile(IN CONST PWCHAR ConfigDirectory,
+                         IN CONST PWCHAR ConfigFile,
+                         OUT PCHAR *ConfigData);
+
 XTCDECL
 VOID
 BlpParseCommandLineOptions(VOID);